Rotary cutting dies are commonly used for producing a container or carton blank from corrugated board sheet material. Such rotary dies are typically comprised of a die cylinder, a die board mounted on the die cylinder and including cutting blades and scoring rules, and an anvil mounted adjacently the die cylinder and the die board. A nip is defined between the die board and the anvil and sheets of corrugated board are fed into the nip. As the corrugated board is fed through the nip, the cutting rules, scoring rules and other devices and elements mounted on the die board engage and operate on the corrugated board passing through the nip and between the die board and the anvil.
Most die boards are designed to trim the corrugated board along surrounding edges as the corrugated board passes through the nip. To accomplish this, the die board is provided with a series of trim cutting blades. Also mounted to the die board adjacent the outside of the respective trim cutting blades is elastomer trim transfer devices or trim strippers. The trim strippers are compressible and resilient. During the trim cutting process, the trim strippers engage the cut pieces of trim as they pass through the nip and hold the cut pieces of trim against the anvil for a short period of time. The trim strippers function to separate the cut pieces of trim from the resulting product board.
Over a period of time, the trim strippers or trim transfer devices tend to separate and move away from the adjacent trim cutting blades. That is, as the trim strippers are compressed and passed through the nip, it is common to find that they tend to bow and as they bow, a small gap occurs between the trip strippers and the adjacent trim cutting blades. Once this gap occurs, it is common for small pieces of cut trim to become lodged or packed in the gap. Over a period of time, this cut trim becomes more compact and is effectively driven down between the trim strippers and the trim cutting blades. The forces placed on the cut pieces of trim can be so great that they damage and even break the die board.